The current standard cathode material in medical lithium batteries (e.g. a defibrillator battery) is silver vanadium oxide (SVO) material represented by atomic formula Ag2V4O11. Although SVO material has a high theoretical capacity of 450 mAh/g (milliampere hour per gram), not all of this capacity is accessible at practical voltages. For example, the open circuit potential of SVO material versus lithium (anode) is 3.25 V. During discharge, the cathode inserts seven lithium ions until it reaches a cut-off voltage of 1.5 V, resulting in a total practical capacity of 315 mAh/g. Initially, the lithium reduces the Ag+ to Ag0 at around 3.25 V, which is the potential at which a defibrillator operates most efficiently. The lithium continues to react and reduces the V5+ to V4+ at 2.5 V. However, the potential does not plateau for the final reduction of V4+ to V3+ but instead it drops precipitously to the cut-off voltage. As a result of the low reduction potential, the full theoretical capacity of SVO is not utilized in practical applications since a voltage below 1.5 V is too low to supply the power (power equals current times voltage) needed for a defibrillator. The medical battery industry desires battery cathode materials that can maintain a potential above 3 V for extended periods of time so as to optimize defibrillator function.